There is no pretty way to do this. I describe this as the “one hop rule” of Webflow’s CMS.
But, let’s assume that you have a fairly rigid 1:n structure here, of;
category <- subcategory <- practice
Each practice is in one and only one subcategory. Each subcategory is in one and only one category.
Then, you can sort of hack this, by putting the burden on subcategory, and enforcing the 1:n structure yourself. To do that, you’d flip the relationship between subcategory and practice so that subcategory has a multiref field to practice.
category <- subcategory => practice
Then you’re working within the one-hop rule.
On the practice CMS page, you drop a collection list bound to subcategory, which is filtered to only show subcategories where the practices contains the current practice. If you’ve enforced it well, there will be one and only one match.
Subcategory can also reach category through its single ref.
